Spindle accelerating and braking system



March 19, 1963 w. B. RETZ spmnuz ACCELERATING AND BRAKING SYSTEM 5Sheets-Sheet 1 Filed March 31, 1960 INVENTOR. WILLIAM B. RETZ ATTORNEYSMarch 19, 1963 w. B. RETZ 3,081,523

SPINDLE ACCELERATING AND BRAKING SYSTEM Q Filed March 51. 1960 5Sheets-Sheet 2 (\l 9 .3 LL

d I, x- PI r-ln I d k W IO a.

L I I i INVENTOR.

WILLIAM B. RETZ ATTORNEYS March 19, 1963 W. B. RETZ SPINDLE ACCELERATINGAND BRAKING SYSTEM Filed March 31, 1960 5 Sheets-Sheet 3 FIG. 3

INVENTOR. WILLIAM B. RETZ M/M/ @M ATTORNEYS w. B. RE' I'Z 3,081,523SPINDLE ACCELERATING AND BRAKING SYSTEM Filed March 31. 1960 March 19,1963 5 Sheets-Sheet 4 FIG. 4

INVEN WILLIAM B. RE

ATTORNEYS March 19, 1963 w. B. RETZ SPINDLE ACCELERATING AND BRAKINGsys'mm 5 Sheets-Sheet 5 Filed March 31, 1960 ATTORNEYS EfihldiidPatented Mar. 19, 1953 3,081,523 SPINDLE ACCELERATENG AND BRAKENGSYSTEh/l William B. Retz, Plainvilie, Conn, assignor to The New BritainMachine Company, New Britain, Conm, a corporation of Connecticut FiledMar. 31, 1960, der. No. 19,028 16 Claims. (Cl. 29-69%) The presentinvention relates to a system for accelerating and braking of spindlesand in particular to means for accelerating and braking individualspindles in a multiple-spindle machine. Specifically, in amultiple-spindle machine wherein there is a continual driving of aplurality of spindles periodically indexed from one station to an otherincluding a chucking or loading station where a spindle is at least fora time stationary, the present invention is concerned with means foraccelerating a spindle, after being stopped at the loading station, upto a common spindle driving means for an operation in a first machiningstation to which the spindle is indexed; and also for braking a spindleto a stop, after disengagement from the driving means, and indexing to aloading station has occurred.

In machines of the character disclosed in the Gridley et a1. U.S. PatentNo. 2,055,434, a barrel or carrier mounting several work chuckingspindles is rotationally indexed periodically to advance each spindlefrom a loading or chucking station to successive stations for particularmachining operations, effected by slide-carried respective tools broughtto and retracted from the rotating spindles in timed relation to thecarrier indexing. In said patent, a continually driven sprocket chain istrained around sprockets of parallel spindles angularly spaced in thecarrier in such fashion that for machining operations at any given timeall except one of the spindles are commonly driven at respectivestations; while the sprocket of the excepted spindle, at the chucking orloading station, is out of driving engagement with the sprocket chain.

A like manner of operation is attained by the generally similar type ofmachine disclosed in the Brown et al. U.S. Patent No. 2,083,312,wherein, however gearing is used commonly to drive the individualspindles, a clutch mechanism and brake mechanism being there used ateach spindle for making a driving connection to the common power sourceand braking of a spindle at appropriate times. In the latter type ofmachine, a drive sleeve coaxial with the rotational axis of an indexingspindle carrier is always meshed with individual input gears ofrespective spindles, each said input gear being in effect thecontinually driven and rotated driving clutch element of a spindleclutch controlling the driving of its respective spindle.

Machines of the types disclosed in both of the aforementioned patents,of course, provide chucking means for gripping a work-piece in arotationally driven relation to each spindle; and also include a timingcamming system for synchronizing indexing of the spindle-carrier, andreciprocation of the tool slide. The gear-driven type also includesmeans for clutching the spindle proper to the driving input of eachspindle assembly as well as means for braking a spindle after releasefrom a driven relation.

Now by the present invention, machines of both drive types are providedwith means whereby a spindle, stopped at a chucking or loading station,is brought up to driving speed before the spindle is engaged with thecommon driving means or system, and further, in the preferred form ofthe invention, a spindle (after release or disengage ment from a suchcommon driving means) is rapidly braked to a stopped condition for aloading or unloading operation. In consequence, a higher spindle drivingspeed is readily attainable for example, on the order of 1000 r.p.m. incomparison with a maximum of about only 320 r.p.m in many cases.

In the case of the gear drive, the individual spindles are driven forthe machining operations by the respective continually driven input gearthrough a positive drive clutch of the spindle unit, and each spindle isbrought up to a speed and braked to a stopped condition by an auxiliarymechanism arranged in a by-passing driving relation to the main drivesystem used for the machining operations.

On the other hand, in the case of the sprocket chaintype drive, inaddition to the spindle drive sprocket (which in conjunction with thedrive sprocket chain may be considered as a positive clutch means byvirtue of the disengagement and engagement of the same upon indexinginto and out of a loading station), each spindle unit or assemblyincludes an accelerating or starting gear engageable by a cammed slidinggear at predetermined time in the indexing cycle for connection with anidler gear operated by an auxiliary spindle starting and brakingmechanism controlling the rotational motion of the spindles from thetime each is brought into the chucking station to the time each isadvanced therefrom to a first work station.

An object of the present invention is to provide in a multiple-spindlemachine means for bringing a stopped spindle up to speed beforeengagement with continually operating driving means. Another object isto provide means for rapidly bringing a spindle to a stop afterdisengagement from a spindle driving means.

A further object is to achieve higher spindle operating speeds byproviding means for accelerating and for braking spindles at the time ofindexing out of and into a loading or chucking station. Another objectis to achieve in a multiple spindle machine starting and stopping ofindividual spindles by use of single clutch means and brake means forsuch purpose. Other objects and advantages will appear from thefollowing description and the drawings, wherein:

FIG. 1 is a schematic or generalized representation of a drive systemfor a multiple spindle machine with gearing driven spindle involving thepresent invention;

FIG. 2 is a fragmentary detail view of spindle unit in a machine of thetype corresponding to FIG. 1;

FIG. 2A is a side elevation of a spindle clutch actuating cam;

FIG. 3 is a fragmentary representation of a sprocket chain drive for amultiple-spindle machine involving the present invention;

FIG. 4 is a section view taken substantially along the line 4-4 in FIG.3;

FIG. 4A is a side elevation of a sliding gear actuating cam;

FIG. 5 is a graphical diagram of a suitable sequence of operations for amachine embodying this invention; and,

FIG. 6 is a schematic representation of the primary elements of one formof timing control for the clutching and braking functions.

An embodiment of the invention adapted to a machine with a spindle drivesuch as that disclosed in the Brown and Retz U.S. Patent No. 2,083,312of June 8, 1937, is shown in fragmentary FIGS. 1 and 2, wherein thepertinent parts of the main spindle drive mechanism of the latter patentand the present auxiliary spindle starting and braking mechanism areshown in more or less schematic form.

A plurality of like equi-spaced spindle units 12 are individuallyrotatable in a carrier 10 mounted for rotation on axis 10' in themachine frame, the carrier here shown including a rear plate 16aperipherally toothed to form part of an indexing mechanism such as thatdisclosed in the Barry and Retz U.S. Patent 2,639,492 of May 26, 1953.

Here a central drive sleeve 13, parallel to the spindles and coaxialwith the spindle carrier 10, through a central gear 14 constantlyrotates drive or input gears 15 for respective spindle units, thespindles proper 16 being respectively driven through spindle clutches 17hereinafter described. The central drive sleeve is driven from motor 2%through a sprocket chain connection 21 to a constant speed shaft 22, thespeed change gears 23 and 24 on shafts 22 and 25 respectively, and gears26 and 27 on shaft 25 and the drive sleeve; the constant speed shaft 22also serving to drive through reduction gearing 31 and a clutch unit 32other mechanism of the machine including a main cam shaft 30.

Specifically pertinent to the present invention, the spindle clutches 17are positive clutches, cam actuated as hereinafter detailed relative toFIG. 2, upon indexing rotation of the spindle carrier; and an auxiliaryspindle drive and brake mechanism is provided. The auxiliary mechanismincludes a starter gear 34 for each spindle, a shaft 35 mounted in theframe and driven by gears 36 and 37 from the constant speed shaft 22, astarting clutch unit 49 for coupling the frame-mounted shafts 35 and 38,a brake unit 41 for braking the latter shaft, a gear 39 secured to thelatter shaft and having width sufficient to maintain mesh with gear 42,which is slidable on shaft 43 into and out of engagement with a startergear 34 of a spindle brought into the loading station.

A speed responsive device 33a driven by or sensing speed of shaft 38includes a switch 38b actuated at a speed in 38 indicative of attainmentof cutting speed by the accelerated spindle, to afford an interlock aslater detailed between operation of clutch 4t and the indexingmechanism. The clutch and brake units 40 and 41 are preferablyelectromagnetic units of self-adjusting types actuated through suitablemechanical-electrical controls at appropriate times as hereinafterdescribed.

The spindle units or assemblies comprise a general structure known tothe art. Each includes the forward bearings 45' and 46 spaced by aninterposed sleeve and secured between nut 47 and a shoulder on theforward end of the hollow spindle 16; the whole being retained in acorresponding bore of the carrier by a circumferential lip or flange 43on the outer race of bearing 45 engaged between the carrier face and aclamping ring 49 bolted thereto, a suitable rotary seal assembly 56being mounted on the ring 49. Rear support is afforded the spindleassembly in plate 16a by bearing 52 on the sleeve-like extension 53a ofa chucking cylinder unit 53 keyed on the reduced end of spindle l6 andaxially secured "thereto by wedging conical or taper point screws 54;the inner races of bearing 52 and of the spindle drive gear bearing 55,with an interposed spacer, being clamped between shoulders on housing 53and spindle 1-6 by the action of the taper screws 54. For pneumaticallyor hydraulically powered or actuated work-piece chucking in a chuck (notshown) to be mounted on the front of the spindle, a rod 56, biased byspring 57 interposed between rod collar 56a and a short sleeve 53threaded into the spindle bore, connects the piston of unit 53 toreciprocable actuating means of the chuck, the actuating fluid beingsupplied and exhausted from unit 53 through a rotary connection 59 in awell-known arrangement.

However, here a starter gear is provided on the spindle in the form of apointed tooth ring gear 34 secured on the housing of unit 53 and therebyto the spindle; and the positive spindle clutch 17 is the only clutchdevice needed in the assembly. The annular driving clutch element 17b(bolted to one face of the driving gear 15', thereby clamping the outerrace of bearing and the driven collar element 17a splined to spindle 16have opposed dog tooth clutching faces to provide a positive clutch; andnormally 17a is slid into engagement by helical clutch spring 170. Foreach spindle assembly, there is a clutch fork or yoke 61 axiallyshiftable in the spindle carrier and engaged in a circumferential grooveA on the shiftable member 17a; which fork serves as a shipper todisengage the clutch 17 when, upon spindle indexing to the loadingstation, roller 62 on the shipper encounters a stationary cam 63 fixedat an appropriate location on the machine frame indicated in fragmentarymanner at 11.

With the arrangement thus far described, the clutch 17 of a spindle unitbeing indexed into the loading station is first disengaged by cam 63 tofree the spindle 16 from the main drive system. Then sliding gear '42,previously shifted out of the path of the incoming starter gear, isshifted into engagement with the starter gear 34 of the spindle in theloading station, and the brake unit 41 engages to brake shaft 38 to astop and thereby the spindle also through gears 39, 42 and 34. It shouldbe noted that indexing need not be completed, that the sliding gear canbe shifted toward the starting gear, as soon as the relative positionsof the gears will permit meshing.

After the previous workpiece has been replaced by a new piece at theloading station, brake 41 is disengaged and then clutch 49 is engaged,so that the spindle at the working station is now driven from constantspeed shaft 22 (through gears 37, 36, shaft 35, clutch 40, shaft 38 andgears 39, 42 and 34) for acceleration of the spindle to working speed,before indexing toward the first work station and the concomitantrelease of clutch 17 into spindle driving engagement occurs. Thepreferred sequence at this point is that gear 42 be shifted out of meshwith the starter gear 34 and then the clutch 46 be disengaged beforeindexing again takes place; but in any event 42 is-disengaged before thespindle clutch 17 engages.

The sliding gear 42 may be spring biased axially toward the positionWhere it is meshed Wtih a spindle starter gear 34 at the loadingstation, and slid out of such position and released into such meshedrelation by a cam mechanism involving a respective cam associated on thespindle carrier with each spindle; such an arrangement being similar tothat hereinafter described relative to the embodiment of the inventionfor the sprocket chain drive of FIGS. 3 and 4. However, the gear 42 mayalso be shifted out of mesh by a shipper or fork engaged in hub groove42a and either mechanically or solenoidally actuated at appropriatelytimed points in the indexing cycle; for which purpose the solenoid maybe subject to the control of a limit switch operated by a cam on a mainfeed control cam shaft or drum, or by cams on the carrier correspondingto respective spindles.

Where the rotational movement of the auxiliary spindle drive is obtainedas in FIGS. 14 from the main spindle driving mechanism of the machinerather than from an independent motor, the various gearing ratios shouldof course be such that the ultimate speed of the spindle derived fromthe auxiliary system will equal the main or cutting speed.

The primary mechanical features of the invention as embodied in achain-type drive (FIGS. 3 and 4) will be described before setting forthcontrol means for timing operations of the auxiliary spindle driving andbraking means relative to each other and to the spindle indexing of themachine incorporating the same.

In FIGS. 3 and 4 of the drawing there are shown the pertinent parts of amultiple spindle metal working machine, generally of the sprocket-chaindriven spindle type disclosed in the aforementioned Gridley et al. US.Patent 2,055,434, and also embodying the present invention.

Again a spindle carrier barrel member it) is rotatably indexablysupported in the cradle or frame .11 for advancing the several likespindle units "'12 from one station to another, for example, in themanner disclosed in the aforementioned Gridley patent; each spindle unitincluding a chucking mechanism (not shown) for engaging a work-piece tobe rotationally driven by the spin-.

dle 216 having a spindle sprocket 214 engageable with a driving sprocketchain 215 continually driven by the drive sprocket 213 keyed to a maindrive shaft 217. The general organization of the machine, and theelements thus far described, and their functions are such as those ofthe prior art disclosed in the aforementioned Gridley patent.

However, the main drive shaft 217 has a gear 220 keyed thereto and alsoan idler gear 221 rotatably mounted thereon by a suitable bearing, theidler gear being in mesh with a gear 222 keyed to an auxiliary shaft 223rotatably mounted in a part of the machine frame ill. Also keyed toshaft 223 is a rotary member 22451 of a magnetic brake 224 including astationary brake member 2241; affixed to the machine frame; also keyedto shaft 223 is the driven member 225a of a magnetic clutch 225. Themagnetic clutch includes a driving member 22512 rotatably bearinged onshaft 223 and secured to a gear 226 in constant mesh with the main shaftgear 220. Thus, the idler gear may be either driven by shaft 223 orbraked relative to the fixed frame 11 upon engagement respectively ofthe magnetic clutch 225 or brake 224; which are no further detailedhere, there being many suitable such devices known to the prior art.

In the specific embodiment of the invention, shown in the drawings withthe axial location of a spindle in the loading station coplanar with theaxes of main drive shaft 217 and of the carrier, a sliding gear 227 inconstant mesh with idler gear 221 is rotatably mounted though axiallyfixed on a non-rotatable shaft 228 axially shiftably mounted in bracketor guide elements 229, 230 fixed relative to the machine frame Ill. Theshaft 228 and hence sliding gear 227 is biased inwardly towardengagement (to the right in FIG. 3) by compression spring 231 interposedon the shaft 228 between the guide element 2-29, and the inner race ofthe bearing for the sliding gear.

The teeth of the idler gear, as may be noted in FIG. 3, are ofsuificient width for maintaining meshed relation with the sliding gearduring axial excursions of the latter, into and out of engagement withstarter gears 2,33 rotationally secured to the respective spindles inthe manner to be described, the teeth of the starter gears being pointedon the outboard (in FIG. 3 left) side, to permit ready engagement of thesliding gear therewith.

The location of the sliding gear shaft, and the pitch diameter of thesliding gear relative to the idler gear and to the starter gear of aspindle in the chucking or loading station, are selected so that theidler gear and such starter gear can be engaged when the spindle inquestion is in the loading station.

For shifting the sliding gear and shaft 228, a radial arm 235'projecting from the tubular guide bracket 230 carries a cam roller 236disposed in the path of like cams 237, each similarly disposed relativeto a respective spindle unit 12 and secured to an end wall of thespindle carrier 16 Each cam 237 has a sloped forward end 237a, a fiatarea 2371) lying in a plane tangential to carrier 10, and an abruptlyterminating trailing end 23%, whereby during indexing movement thesliding gear is moved and held out of the path of the incoming startergear until the latter has come to position where it may be slidablyengaged by the sliding gear, at which point the cam roller escapes thecam, permitting spring 231 to shift the sliding gear into engagementwith the starter gear.

Here again each pointed tooth starter gear 233 is shown as secured on achuck fluid power cylinder 253 secured on the back end of a spindle 216for rotation therewith, but arranged for example, as in theaforementioned Gridley patent for distribution and valving of theoperating fluid.

In the contemplated manner of operation, the mag netic clutch 225 andmagnetic brake 224 are both deenergized, therefore disengaged, duringindexing; a spindle having been reloaded With a new Work-piece at aloading station is brought up to speed by energization and engagement ofclutch 225 before a next indexing motion of the carrier begins, againwith an interlock, e.g., between clutch and indexing means, to insurethat this occurs; and the brake is automatically engaged immediatelyafter indexing of a spindle into the loading station.

Generally with this chain type drive the positive spindle clutches 17 ofFIGS. 1 and 2 will not be required, since the disengagement andengagement of a spindle sprocket with the drive chain in indexing in andout of the loading station provides a positive clutch function withrespect to the continually operating main drive system for the spindles.

The sequence of events characteristic of operation of a machineembodying the present invention is graphically represented in FIG. 5,with the rotation of a main feed cam or cam shaft used as a basis forreference. In machines of this general character, a single rotation ofthe feed cam or shaft represents a single cycle of machine operationbeginning after an indexing of the carrier; during the first 270 ofwhich, tool feed advance, cutting at the work stations and rapid toolretraction occurs, with unloading and reloading of the spindle at theunloading station; and in the last of which indexing takes place.

FIG. 5 is concerned principally with events occurring at a spindle(denominated #1 spindle) indexed during a first cycle from the last workstation into the loading station, and thereafter during a followingcycle indexed into the first work station; the vertically off-setportions of the line representing the period of actual indexingmovement.

First, at A the sliding gear 42 (or 227) is shifted out of the path ofthe spindle starting gear 34 (or 233) coming into the loading station;at B, the engagement with cam 63 of the roller 62 on clutch fork 61disengages a positive clutch 17 (or a #1 spindle sprocket disengagesfrom the drive chain); and at C, with indexing completed and the carrierstationary (for specific machining operations at each station), thesliding gear re-engages with the starter gear newly come into theloading station, while Ibraking by 41 (or 224) begins.

For the same (#1) spindle in the next cycle (or of course, the spindleimmediately in advance thereof during the same cycle), I representscompletion of spindle braking begun by 41 (or 224-) at or shortly afterC; K the completion of the operations of unloading a finished piece andloading of a new piece; L engagement of the electromagnetic clutch 40(or 225) to accelerate the newly loaded (#1) spindle to normal directdriving or cutting speed; M the disengagement of the electromagenticclutch before indexing begins, with cam shifting of the sliding gear 42(or 227) out of mesh occurring shortly thereafter at A by removing slidegear 42 from the path of the incoming next (#2) spindle starting gear;and N the reengagement of the #1 spindle clutch (or of the sprocketdrive spindle with the drive chain) to effect a driving by the mainspindle drive.

Particularly where a relatively long cutting time is required for anoperation at one of the work stations, the rapid braking of the spindlein the work station can provide time during the dwell of a spindle inwhich an additional operation may be there carried out, either on awork-piece about to be unloaded or a new piece; the location of theadditional operation depending upon its character, whether on a new orold piece and the particular control and actuating means adapted forauxiliary drive, clutch, brake and where used spindle clutches.

Here it may be noted that, in a multiple-spindle machine embodying thepresent invention, advantageously there may :be incorporated means todisengage the feed clutch in the event a work-piece is not chucked (e.g.the expedient disclosed in the Brown US. Patent 2,083,312 of June 8,1937; FIGS. 11, 12, 13 thereof, and associated description); or thereoccurs any other malfunction to be met by such Brown disclosure.

To time the operations of the clutch and the brake in the auxiliarysystem, various mechanical or electricalmechanical expedients areavailable. For example, with manually disabled indexing mechanism suchas that disclosed in the above named Barry and Retz U.S. Patent2,639,493, the electro-mechanical timing control means of schematic FIG.6 may be used, wherein the disabling clutch of said patent (forpreventing normal indexing of the spindle carrier in the course of arotation of cam shaft 30) is represented .by 264), but with the clutchin contrast here being biased to a disengaged condition. The clutch 260,adapted to engage at only one relative position of its driving anddriven members, according to said patent then controls a Genevamechanism effecting the indexing. Further, according to FIG. 6,energization of solenoidal means 261 serves to keep clutch 260 engaged(against the spring bias) for normal operation, but deenergizationcauses disengagement, thereby to prevent spindle carrier indexing. Thismodification of the Barry- Retz patent arrangement is intended, inconjunction with the control circuitry next described for provision ofan interlock between the auxiliary clutch 40 (or 225) and the indexingmechanism, to prevent indexing of a spindle from the loading stationwhich has not been brought u tospeed.

The auxiliary clutch 40 (or 225) is energized for en gagernent byclosure of a normally open cam actuated switch 262 in series therewithacross a suitable power source, e.g., a micro-switch closed by a cam 264(on the main feed cam shaft 36) for the portion of the cycle allotted tospindle acceleration. In similar manner the brake '41 (or 224) isenergized to engaged condition by closure of switch 265 by a earn 266preferably also on shift 39, although cams on the carrier appropriatelylocated relative to respective spindles could be used to actuate such aswitch.

The solenoid of 261 is connected to a suitable power source throughnormally-open contacts 267a of a relay; and the relay solenoid 2670 inturn is connected to the power source through normally-closed contactsof a switch 268, while other normally-open cam operated switch contacts269 are connected in series between 2670 and speed responsive switch 38b(here shown as normally open), i.e., the series of 269 and 38b being inparallel with 268.

By a further cam means 270* on shaft 30, there is actuation of switch268 to open condition and of switch 269 to closed condition forinspection of the speed of the spindle to have been accelerated so thatif any malfunction in the auxiliary drive system results in a failure ofthe spindle to come up to a minimum desired speed before indexing, theclutch 2 66 will open to prevent indexing. The manner of operation ofthis form of control with interlock is as follows: Switch 262 is closedby earn 264 (at point L, FIG. 5 energizing the auxiliary drive clutchthereby to accelerate the spindle in the loading station. Attainment ofa suitable spindle speed will be represented by a definite speed inshaft 38 which closes switch 38b. At a point in the cycle of rotation ofshaft 30, and shortly before indexing is to begin, cam means 270 throws268 open and 269 closed. With 38b closed, the closing of 269 continuesthe energization of 2670, and therefore keeps normallyopen contacts 267aclosed and indexing clutch 26% engaged so that indexing is carried outin a normal cycle of operation.

Were a malfunction in the auxiliary drive to occur, resulting in thenewly-loaded spindle not being brought up to speed, contacts 33b wouldthen be open at the time 268 opens to turn over control to 269; thiswould result in deenergization of relay coil 267s and attendant openingof contacts 267a, thereby deenergizing solenoid 261 and allowing theindexing clutch 261 to open and prevent indexing. Even though closing of263 after transit of cam-276 results in energization of solenoid 261,tending to engage clutch 266, no indexing will take place during afollowing revolution of shaft 36, assuming the malfunction to persist,since the described control sequence will again be repeated to put thespindle in question again under the inspection of the circuit branchinvolving 38b.

In the above system, contacts 268, 269 may comprise a singlecam-operated switch unit; and since in the actuation thereof from onecondition to the other, both might be simultaneously open, contacts 267athen should be delayed opening contacts, with opening-delay timesufficient to permit the actuation of 268--269 from normal toanti-normal condition without affecting clutch 266; or alternatively, amechanical linkage from a camfollower of 27% may be used involving alost motion connection to 268 permitting 269 to close before opening of268.

While I have described the invention in detail for the preferred formsshown, it will be understood that modifications may be made withoutdeparting from the invention as defined in the claims which follow.

I claim:

1. In a machine of the character described, a spindle carrier rotatablymounting a plurality of spindles and rototable indexibly mounted in themachine frame; starter gears secured for rotation with respectivespindles; main drive means simultaneously driving all spindles except atleast one spindle located in a loading station; carrier indexing meansfor disengaging each spindle from and positively engaging it with saidmain drive means respectively as it is indexed into and out of saidstation; a shaft rotatable in the frame driven in constant relation withsaid main drive means; a gear rotatably supported on the frame andaxially slidable into engagement with a spindle starter gear in theloading station; a second gear rotatably supported by the frame andmeshed with the slidable gear; means for shifting said sliding gear intoand out of engagement with a spindle starter gear respectively uponindexing the respective spindle into the loading station and when thespindle has been loaded with a work-piece; brake means for stopping saidsecond gear and thereby a spindle after indexing into the said station;the shifting means including a shipper on the frame, and a cam on thecarrier for each respective spindle; clutch means for coupling saidsecond gear to said shaft whereby a spindle loaded in-said station maybe accelerated to spindle driving speed before indexing from saidstation.

2. In a machine of the character described, a spindle carrier rotatablyindexably mounted in the machine frame and rotatably mounting aplurality of spindle assemblies; each assembly including a work drivingspindle, a spindle input gear and positive clutch means for engaging thespindle with said input gear; said clutch means having an actuatingelement projecting from the carrier; a continually rotating centraldrive gear meshed with all said input gears to provide a main drive forthe spindles; means on the frame in a loading station region andengageable with the said actuating element of a spindle assembly todisengage each spindle from and engage it with said main driven meansrespectively upon indexing into and out of said station; acontinually-driven shaft rotatable in the frame; rotary means on theframe rotationally engageable with a spindle in the loading station;means for shifting said rotary means into and out of engagement with aspindle respectively when the spindle has been indexed into the loadingstation and when the spindle has been loaded with a work-piece; brakemeans for stopping said rotary means and thereby a spindle afterindexing into the said station; clutch means for-coupling said rotarymeans to said shaft whereby a spindle loaded in said station may beaccelerated to spindle driving speed before indexing from said station.

3. In a machine of the character described, a spindle carrier rotatablyindexably mounted in the machine frame and rotatably mounting aplurality of spindle assemblies;

each assembly including a work driving spindle and a spindle drivesprocket thereon; a continually driven sprocket drive chain trainedabout the drive sprockets of the spindles, excepting a spindle in a Workstation to provide a main drive for the spindles; a continually drivenshaft rotatable in the frame; rotary means on the frame rotationallyengageable with a spindle in the loading station; means for shiftingsaid rotary means into and out of engagement with a spindle respectivelywhen the spindle has been indexed into the loading station and when thespindle has been loaded with a work-piece; brake means for stopping saidrotary means and thereby a spindle after indexing into the said station;clutch means for coupling said rotary means to said shaft whereby aspindle loaded in said station may be accelerated to spindle drivingspeed before indexing from said station.

4. In a machine of the character described including a spindle carrierrotationally indexable in the machine frame, means for indexing thecarrier, a plurality of spindles rotatably mounted therein, and meansfor simultaneously driving all but at least one of said spindles locatedin a loading station, the combination comprising: means for disengagingeach spindle from and re-engaging it with the driving means uponindexing into and out of the loading station respectively, and an aux-.iliary spindle braking and accelerating system for quickly stopping aspindle before a loading station operation, and accelerating the same tospindle drive speed before indexing out of the loading station; saidsystem including a starter gear on each spindle, a second gear rotatablymounted on said frame, a shiftable gear mounted in the frame shiftablefrom a position of engagement with both a starter gear at the loadingstation and said second gear to a position out of the path of a startergear coming into the loading station, means for shifting the gear out ofsaid path during indexing carrier movement and into engaged position oncompletion of indexing, brake means for stopping said second gear andthereby a spindle indexed into the loading station, and means includinga clutch for connecting said second gear to a constantly driven shaft toaccelerate a loaded spindle to a speed approximating spindle speedobtained from the drive means.

5. In a machine as described in claim 4, cam means for shifting saidshiftable gear in and out of engaged position, said cam means includinga cam on the carrier for each respective spindle.

6. In a machine as described in claim 4, timing cam controlled means forengaging and releasing said brake means and said clutch at predeterminedtimes in relation to an indexing cycle of the machine.

7. In a machine as described in claim 6, interlock means between theclutch means and the indexing mechanism for preventing indexing uponfailure of a spindle to accelerate to a preselected speed at the loadingstation.

8. In a machine as described in claim 7, said interlock means includinga speed responsive switch sensing the speed of a rotary element in theline of motion transmission from said clutch to said starter gears.

9. In a machine as described in claim 4, said driving means comprising acontinuously driven central gear coaxial with the carrier, input gearson respective spindles and constantly meshed with the central gear, anda cam actuated positive clutch on each spindle for clutching the spindleand input gear; said clutch being actuated upon successive indexingmotions of said carrier to disengage and reengage.

10. In a machine as described in claim 4, said driving comprising adrive sprocket on each spindle and a continuously driven endlesssprocket chain trained over all spindles outside of the loading station.

References Cited in the file of this patent UNITED STATES PATENTS1,984,052 Bollard Dec. 11, 1934 2,646,152 RetZ July 21, 1953 2,876,527Matlachowsky Mar. 10, 1959

1. IN A MACHINE OF THE CHARACTER DESCRIBED, A SPINDLE CARRIER ROTATABLYMOUNTING A PLURALITY OF SPINDLES AND ROTOTABLE INDEXIBLY MOUNTED IN THEMACHINE FRAME; STARTER GEARS SECURED FOR ROTATION WITH RESPECTIVESPINDLES; MAIN DRIVE MEANS SIMULTANEOUSLY DRIVING ALL SPINDLES EXCEPT ATLEAST ONE SPINDLE LOCATED IN A LOADING STATION; CARRIER INDEXING MEANSFOR DISENGAGING EACH SPINDLE FROM AND POSITIVELY ENGAGING IT WITH SAIDMAIN DRIVE MEANS RESPECTIVELY AS IT IS INDEXED INTO AND OUT OF SAIDSTATION; A SHAFT ROTATABLE IN THE FRAME DRIVEN IN CONSTANT RELATION WITHSAID MAIN DRIVE MEANS; A GEAR ROTATABLY SUPPORTED ON THE FRAME ANDAXIALLY SLIDABLE INTO ENGAGEMENT WITH A SPINDLE STARTER GEAR IN THELOADING STATION; A SECOND GEAR ROTATABLY SUPPORTED BY THE FRAME ANDMESHED WITH THE SLIDABLE GEAR; MEANS FOR SHIFTING SAID SLIDING GEAR INTOAND OUT OF ENGAGEMENT WITH A SPINDLE STARTER GEAR RESPECTIVELY UPONINDEXING THE RESPECTIVE SPINDLE INTO THE LOADING STATION AND WHEN THESPINDLE HAS BEEN LOADED WITH A WORK-PIECE; BRAKE MEANS FOR STOPPING SAIDSECOND GEAR AND THEREBY A SPINDLE AFTER INDEXING INTO THE SAID STATION;THE SHIFTING MEANS INCLUDING A SHIPPER ON THE FRAME, AND A CAM ON THECARRIER FOR EACH RESPECTIVE SPINDLE; CLUTCH MEANS FOR COUPLING SAIDSECOND GEAR TO SAID SHAFT WHEREBY A SPINDLE LOADED IN SAID STATION MAYBE ACCELERATED TO SPINDLE DRIVING SPEED BEFORE INDEXING FROM SAIDSTATION.